"Infatigable" is a word in ENGLISH

To hunt or track like a hound; to follow insidiously or indefatigably; to chase with a dog or dogs; to …

The state of being indefatigable.

Incapable of being fatigued; not readily exhausted; unremitting in labor or effort; untiring; unwearying; not yielding to fatigue; as, indefatigable …

Indefatigable quality; unweariedness; persistency.

Without weariness; without yielding to fatigue; persistently.

Indefatigableness; unweariedness.

písan - To be or become diligent, assiduous, zealous, active, energetic, indefatigable, hardworking; to apply oneself to with zeal, perform …

Indefatigable.

Not wearied; not fatigued or tired; hence, persistent; not tiring or wearying; indefatigable.